If you're planning to cut and solder a PL-259 connection onto CB coax, you'll need a coax reducer along with the PL-259 connection. Be sure to choose the proper reducer, as the size of RG58 coax differs from that of RG59 (dual antenna) or RG8X coax cable.

These reducers are made from nickel-plated brass and are available in two sizes. One reducer is used with thinner RG-58 CB coax cable, while the other is used with larger cable, such as RG-59 (co-phased) and RG8X / mini-8 coax.